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Optical Storage the Backup King!

January 16, 2022

phenixnuner

People when backing up data like to focus on speed and apparent ease. This is why people mainly focus on portable hard drives or SSDs for backup solutions. While easy to copy and paste on they are easily damaged, very expensive and slower compared to desktop hard drives. Another disadvantage of the hard drive solution is determining the formatting. I simple will argue why you should consider blu-rays as your onsite backup medium.

Blu-ray Filesystem Advantage

While not thought of very often in the case of backing up data Filesystems are very important. Filesystems are how a computers understand the contents of storage drive. For instance Mac Formatted hard drives cannot be read without additional software on other operating systems. An NTFS hard drive is read only on MacOS. Some older portable drive formats also limit the file sizes that can be stored on them and have naming limitations. This means that you could have the storage space available to hold your Data ,but due to the name or file size it could not be backed up to your drive. Reformatting your drive causes all the data to be deleted off the drive so you have to transfer all the data off to put one file on. While optical storage including Blu-ray use the UDF (Universal Disk Format) which is vender independent and can support massive files and is natively supported in MacOS, Linux & Windows. Which makes it an excellent way to store your files platform independently. 

Write Only and Storage Drive

Most of the blu-ray disk your going to find are Write only which for a hard drive is a pain, but for backup it isn’t. When you are backing up photos, home videos, music or movies you do not want them to be changed. When backing up this data the the whole point is to not lose it or have to be changed. Write only memory cannot be corrupted when the reading device loses power. Blu-rays are Impervious to powerful magnets so they beat hard drive storage and flash storage in this regard. Another big benefit of Blu-rays is that the storage media is separated form the playback device. If a hard drive’s read head dies the data could be fine but it impossible to read and SSDs have the same problem with a dead controller. This is a massive advantage because replacing a broken Blu-ray drive allows access to data while replacing the read head of a hard drive or SSD controller is expensive and difficult. An unforeseen advantage of the Read Only nature of the data is that it is immune encryption based ransomware since the data cannot be modified.

The format is backward compatible 

A Blu-ray drive can read CD and DVDs which makes it more than a one trick pony. This seems trivial until you realize that electrical interfaces for internal storage have drastically changed just over my lifetime with following set of connectors IDE, SCSI, SATA (I,II &III), MSATA, SATA Express, M.2 & U.2. External interfaces have changed from USB mini, USB micro, eSATA, Firewire 400, Firewire 800, Thunderbolt 1, Thunderbolt 2 and Thunderbolt 3. While with a single drive you are able to access data from 1983 till the present.

Isn’t Optical Media Slow?

To put this to the test I created a Test set for transfer speed to compare real world performance. It was broken down into three groups pictures, sound and video. In the pictures I had the pictures and video from a trip I took during graduate school which totaled 8.7GB including mainly pictures and some short videos. In the sound category I have Led Zeppelin’s entire Discography in CD quality FLAC, A copy of the En Avant! Audio companion CDs and Finally Mike Dean’s 420 & 422 in HiRes FLAC. On the Video section I had DVD rip of the first season of The Batman, Rosewood in 1080p, The Recording of Underoath playing “LOST IN THE SOUND OF SEPARATION TRANSMISSION” and finally HDR test patterns. The Performance was carried out by copying files to and from the WD NVME drive which is assumed to be faster than the rest of the drives but can not be profiled as you cannot fairly copy to the drive itself. The test depended on the drives bottlenecking the WD NVME drive. The Access time was found by using Gnome’s built in drive benchmark tool using a file size of 954MiB to cause a cache overflow on the drives with known cache sizes. A cache overflow just means that if a drive has a fast memory cache on the device if the file transferring is larger than this it will have to access the slower drive. This is like fusion drive which had a mix of a hard drive and an SSD if you transfer a file larger than the fast SSD you would be limited to hard drive speeds.

I have benchmarked several storage disk below.

ModelRead / Download (Megabit/s)Write / Upload (Megabit/s)Access Time (ms)Estimated Cache Size (Megabyte)GigaByte/($ USD)
WD_BLACK D10 8TB1886178211.7425640
256GB PRO Elite22297610.42Unknown4.97
16GB268401.08Unknown0.94
WD_BLACK SN750 NVMe? (due to testing)? (due to testing)0.17Unknown6.67
CS900 (120GB)134426680.28Unknown4.29
USA Broadband13419See note*n/an/a
USA Mobile539See Note*n/an/a
WH16NS6018692
Table showing disk speed

*The access time cloud =Time spent downloading the file +the disk access time

MakeModelModel Numer
Western DigitalWD_BLACK D10 8TBWDBA3P0080HBK-NESN
PNY256GB PRO EliteP-FD256PRO-GE
Infinitive16GBBL16?425517B
Western DigitalWD_BLACK SN750 NVMeWDBRPG0010BNC-WRSN
PNYCS900 (120GB)SSD7CS900-120-RB
Median USA Fixed BroadbandOokla Nov 2021
Median USA MobileOokla Nov 2021
LGWH16NS606x Dual Layer (50GB) Blu-ray Disc
Test Device Information

Blu-ray is one of the slowest media of the bunch and has awful access time. However, blu-ray is fast enough for all the content and still faster to read and write than the median fixed broadband in the United States which is in the top 10 for speeds. Remember the broadband comparison is for if a cloud storage solution could use all of your internet bandwidth which no cloud storage solution is capable of doing. You may have 10TB of cloud storage but how are you going to download that quickly and reliability in case of a failure.

To put this in to perspective the highest bitrate content I had was a Video captured on my camera at rate of 2.375 MB/s or about 10 times slower than Blu-ray’s peak read speed. I had 4k Freaking test patterns in HDR unable to saturate the read speed. Yes, Blu-ray is slow but vary few files even have peak bitrates that can saturate Blu-rays speed. Very few storage alternatives can beat Blu-ray’s GB per dollar.

Bit Rot and Disk Failure

Many will argue that Blu-ray is a bad format because it is a dying media and can suffer from disk rot ,but hard drives fail all the time. What really matters is what is the quality and longevity of your media that you own and frankly it is impossible to know this fact. You can store them in temperature and humidity controlled environments and still have failures. Another argument against Blu-ray is you will need to make a directory to find all your files because they will span multiple disk. However, storage size and file size have been on the increase for a while it is more likely that you will need to span your data across multiple media anyways. Any storage media will need a distributed file directory so this is once again a moot point. Also, I wanted to avoid talking about high-end backup like LTO (Linear Tape-Open) ,but it will prove my point. This argument argument that hard drives will last for 20 years is a moot point because what are you going to read these files on? I am going to show that interface disappearance is the thing to worry about not so much the underlying media. LTO drives need to at minimum be two generations backwards compatible with reading up to LTO-7. The current LTO standard is 9 which means with two previous versions of support 8 which came out in 2017 which means a current drive can only support media at minimum up to three years ago which is not great. However, LTO-1 was released 20 years ago so that means any LTO-1,LTO-2 or LTO-3 drive should be able to read this media so first lets fine some of these drives. A quick search of Newegg and eBay shows that vast majority of these Drive use the SCSI interface which is not supported by modern computers and would require an adapter. The only real adapter I could find was the Ratoc USB 2.0 to Ultra SCSI Converter which is now discontinued. Unless you can find remaining adapters, the remaining drives and your operating system can read the partition format you are out of luck even reading your 20 year old drives. You can go out and purchase a USB blu-ray drive and read a Blu-ray,DVD or CD you burned on a 2003 Blu-ray drive ,but your new LTO drive will not read your 2003 LTO-3 drive. Disc rot is nowhere near as big as actually being able to read the media and is the same as data loss.

Conclusion

While arguing for Blu-rays I would like to point out that all is not well in burning software it is harder to find and they are relatively unreviewed. So, if you’re on a Mac Roxio’s toast from their site is one of the only software packages available (The Mac App Store one is super old). On Windows you have Roxio and Nero for Blu-ray burning. On linux you can use XFburn or K3b to burn disc. However, I would only recommend using them to create ISO files then burning with xorriso the command line tool (see tips for that). Also, unless large files need to be backed up I the initial cost of a blu-ray drive may break even. However, for the speed, cost per Gigabyte, immunity to power failure, immunity to EMP, immunity to encryption based ransomware attacks I believe Blu-rays are an excellent choice for most people’s Local backup needs.

Backup Tips

  • Never store data in .zip, folders of compressed folder format as you will a program that can uncompress the folders after which may not exist
    • Also, .zip was designed for documents so using it to compress audio, pictures or video is basically pointless. If lossless convert to a lossless format like Flac or Alac. Using CPU encoding you can see massive file size drops going from H.264 to HEVC.
  • On linux the most reliable way to burn to use K3b to create a disk image and then use xorriso to burn the disk with command line. I recommend creating the disk image first the burning the disk image.
    • xorrecord -v dev=/dev/sr0 blank=as_needed -eject padsize=300k ‘.iso’ 
    • The above script has led to fast flawless burns
  • Create a database of stored files on a writeable medium as you will need this to access the data.
  • For backing up to CD or DVD just use the built in utilities on each OS they should be fine.
  • Store on multiple formats
  • Check your Media to make sure the contents still exist
  • Create an List of media Storage
  • Avoid Hard disk in enclosures buy separate disk and enclosures (Portable hard drives or SSDs)
  • Only expect a decade out of your backup and then begin porting as drive and reading will start to become limited
  • RAID storage is not backup it is additional redundancy.

See for Additional information

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